1. Field of the Invention
The present invention relates to a cutter for use in cutting a range of different diameter plastic pipe and tubing. It will be understood that the utility of the cutter is not limited to xe2x80x9cplasticxe2x80x9d or to xe2x80x9cpipe or tubingxe2x80x9d, those terms being used in a non-limiting sense to indicate the type of material to be cut not necessarily the identity of the material such that the term xe2x80x9ccutterxe2x80x9d as used in the subjoined patent claims also includes without limitation a cutter for rubber extrusions and the like.
2. Brief Description of the Prior Art
A cutting tool for cutting plastic pipe and tubing is described in U.S. Pat. No. 4,336,652 to Robertson. The cutter described in this patent is commercially available. For best cutting action, a knife blade should make an angle of about forty-five degrees with respect to the plastic pipe or tubing at initial contact. Since the pivot point of the Robertson cutter is fixed, this can be achieved with different diameter pipe and tubing only by offering the cutter in different sizes. It would be desirable to have a cutter adapted for cutting a range of different diameter plastic pipe and tubing.
The jaw members of a Robertson-style cutter are pivoted open by raking the handle end of the jaw bearing the knife blade across the user""s clothing or body. In cutters dimensioned for use in cutting larger diameter pipe and tubing, the knife blade tends to flex making it very difficult or impossible to make a square cut. Other shortcomings of the Robertson cutter include a two-part construction of the jaw with the knife blade.
In view of the above, it is an object of the present invention to provide a cutter which can be used with a range of different diameter plastic pipe and tubing. It is another object to provide a cutter which minimizes blade flexing for a square cut. It is also an object to provide a cutter wherein the angle of initial contact between the knife and the pipe or tubing approaches optimal for commonly available sizes of pipe or tubing. Other objects and features of the invention will be in part apparent and in part pointed out hereinafter.
In accordance with the invention, a cutter for cutting a range of different diameter plastic pipe and tubing has a pair of jaw members pivotally connected intermediate their ends. A first of the jaw members is pivoted on a pivot pin within a second of the jaw members. The first jaw member has a handle at one end and a knife blade extending from the other end. The knife blade has a longitudinal cutting edge. The other of the jaw members has a handle at one end and a cradle with a generally semi-circular cutting cage at the other end into which the knife blade extends. The pivot pin is longitudinally adjustable in the second jaw member for changing the pivot axis of the first jaw member thereby changing the effective cutting cage of the cradle and the angle at which the cutting edge of the knife blade makes on initial contact with the pipe and tubing.
The invention summarized above comprises the constructions hereinafter described, the scope of the invention being indicated by the subjoined claims.